Greg Yardley captures Omid Kordestani and Sergey Brin back to back from the Web2.0 conference. Kordestani is rather smug in his surety that Google has the click fraud problem under control. Sergey's answer is harder to understand:
Q: Is clickfraud a problem?
A: ... We have fraud teams, a lot of our advertisers (in fact most) care about the conversions, making the sales, and know the exact ROI they’re getting. To them, if there’s a case of click fraud, it’s the same as disinterested clicks - don’t care as much about that, but about the ROI. Doesn’t completely protect people but on the whole clickfraud is kept to a very low level.
When I see that answer, I gotta give Sergey a lot of credit. He's way more honest about it than his lieutenant Kordestani. He's really got a good grasp on things - because he's right - most of his customers know there is a problem, but they are doing well enough that it doesn't matter much to them.